Mn2+-doped ZnS–CdS alloy nanocrystals for the photocatalytic hydrogen evolution reaction

The effect of doping of the Zn_xCd_1−xS (x=0.37–0.50) alloy nanocrystals with Mn²⁺ ions on the rate and apparent quantum yield of the photocatalytic H₂ evolution catalyzed by this alloy has been investigated. It has been found that the ZnS shell significantly increases the lifetime of the Mn²⁺ excited state, which leads to the generation of ‘hot’ electrons and the two-photon photocatalytic reduction of hydrogen ions. An analysis of the characteristics of nanocrystals without a ZnS shell with similar excitation energies of the edge exciton revealed that the efficiency of the alloy doped with Mn²⁺ ions is 1.2–1.3 times higher due to an increase in the lifetime of photoinduced electron–hole pairs.